Advancements in wireless communication technology have greatly increased the versatility of today's wireless communication devices. These advancements have enabled wireless communication devices to evolve from simple mobile telephones and pagers into sophisticated computing devices capable of a wide variety of functionality such as multimedia recording and playback, event scheduling, word processing, e-commerce, etc. As a result, users of today's wireless communication devices are able to perform a wide range of tasks from a single, portable device that conventionally required either multiple devices or larger, non-portable equipment.
Advancements in mobile device technology have also given mobile devices the ability to detect and leverage device/user context information, such as the location of a device, events occurring in the area of the device, etc., in performing and customizing functions of the device. For instance, a mobile device may utilize various techniques to determining whether the device is presently indoors or outdoors. The process of determining whether a mobile device is indoors or outdoors is referred to herein as “indoor/outdoor detection.” Indoor/outdoor detection performed with respect to a mobile device provides general awareness of the indoor/outdoor context to the device, which in turn can enable the device to perform actions such as selectively activating indoor or outdoor positioning services as needed to reduce power usage and/or improve overall user experience.
Various techniques for indoor/outdoor detection utilize WiFi-based solutions, in which the indoor/outdoor status of a mobile device is estimated based at least in part on the presence or absence of detectable WiFi signals from one or more WiFi access points (APs) near the position of the device. However, in WiFi-based solutions, the absence of a detectable AP near the device signifies only that the device is at least a certain distance away from any APs. Based on the absence of detectable WiFi signals alone, a conclusion cannot be drawn as to whether the device is indoors or outdoors.